Sound dampening dome over sump pump

sound-proofingsump-pump

My sump pump is loud. It is right below my bedroom and when it rains at night, it's hard to relax to the sound of the rain when all I hear is the loud grumble of the pump. To make matters worse, I don't have a basement so the pump is only a few feet below my bedroom floor (in the crawl space obviously).

A thought occurred to me but I wanted to get other people's opinions on it. I thought about building a dome out of sound-dampening material that I could place over my sump pump. It would be a rigged solution but I think it might just help. My basic thought is curve sound dampening material into a dome shape, large enough to cover the general area of the pump. Then, mount the dome onto some metal legs that I can then stick into the ground around the pumps location.

Can anybody foresee any caveats to this? Or perhaps suggest a better method or design?

Best Answer

Your idea is sound, pardon the pun. If you are thinking of having a dome shape, consider to construct a geodesic partial sphere/geodesic dome. This design is based on an icosahedron, a 20 face regular polyhedron in which all vertices are coincidental to a sphere. For geodesic structures, each edge is split into two, three, four and rarely five equally divided portions. The vertices which result from these splits are also coincidental to the sphere. The math could be considered daunting in earlier days (last century) but with the internet, the answers abound.

A two frequency geodesic dome/sphere (split each edge in the middle) will have a blocky appearance but fewer unique triangles.

Two frequency dome

A three-frequency dome will be more spherical, but require more triangles, of course.

An easy way to determine the frequency of a geodesic sphere or dome is to locate the points from which five struts/edges radiate, which is the center of a pentagon. Count the number of struts between one center and the next.

When constructing geodesic structures from flat panels, it is considered simpler to assemble these pentagons first, although different sites have different suggestions based on the assembly of each panel, especially if one is building from dimensional lumber and plywood or similar material.

In the case of rigid foam board, you would have to pay close attention to the edge angles and create a miter to accept the adjacent panel, or join only the inner edges and use a foam filler to secure the resulting gap.

3v (three frequency) dome

The lower number frequency reference means larger triangles, while the higher number means smaller area triangles. This can be a factor when dealing with sheet material.

On higher frequency designs, it is common to have 1/2 dome or 5/8 domes, which provide for greater internal vertical clearance without sacrificing ground area.

You should be able to construct a lightweight rigid foam sheet geodesic dome with suitable sound damping (dampening = making wet) properties. Obviously, thicker foam panels will result in greater sound reduction.